Quantum Barkhausen noise induced by domain wall cotunneling
[1];
[1]
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125, Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada, Pacific Institute of Theoretical Physics, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
Most macroscopic magnetic phenomena (including magnetic hysteresis) are typically understood classically. Here, we examine the dynamics of a uniaxial rare-earth ferromagnet deep within the quantum regime, so that domain wall motion, and the associated hysteresis, is initiated by quantum nucleation, which then grows into large-scale domain wall motion, which is observable as an unusual form of Barkhausen noise. We observe noncritical behavior in the resulting avalanche dynamics that only can be explained by going beyond traditional renormalization group methods or classical domain wall models. We find that this “quantum Barkhausen noise” exhibits two distinct mechanisms for domain wall movement, each of which is quantum-mechanical, but with very different dependences on an external magnetic field applied transverse to the spin (Ising) axis. These observations can be understood in terms of the correlated motion of pairs of domain walls, nucleated by cotunneling of plaquettes (sections of domain wall), with plaquette pairs correlated by dipolar interactions; this correlation is suppressed by the transverse field. Similar macroscopic correlations may be expected to appear in the hysteresis of other systems with long-range interactions.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0014866
- OSTI ID:
- 2326265
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 13 Vol. 121; ISSN 0027-8424
- Publisher:
- Proceedings of the National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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